Gold is a precious metal that has been a symbol of wealth since the beginning of time. In its most expensive, pure form of 24 karats, gold is quite soft and malleable. To gain strength and tenacity, gold is commonly combined with other metals, usually with silver and copper in a process called alloying. Although this may decrease the value of the gold slightly, it increases durability and allows gold to be used for long lasting fine jewellery.

Purity

The Gold content in a metal is measured in terms of karats ("k" or "kt"). Pure Gold or 100% Gold is referred to as 24k Gold. When this pure Gold is alloyed with other metals, such as silver, copper, or nickel, the Gold percentage decreases. 18k Gold is 18/24th or 75% pure Gold, and 14k Gold is 14/24 or 58.3% pure Gold. As the percentage of pure Gold decreases, the strength of the metal increases: so 14k Gold is stronger than 18k Gold. Additionally, as the percentage of pure Gold decreases, the price of the metal also decreases: so 14k Gold will cost less than 18k Gold.

24 karat Gold equals 100% pure Gold

Too soft for jewellery

22 karat Gold equals 91.7% Gold

Still too soft for jewellery. Popular in certain parts of the world.

18 karat Gold equals 75% Gold

Very popular for jewellery, good balance of strength and value

14 karat Gold equals 58.3% Gold

Extremely popular for jewellery. Good balance of durability and value.

12 karat Gold equals 50% Gold

Not used for jewellery

10 karat Gold equals 41.7% Gold

Lowest Gold content that can be legally marked as Gold in the United States.

Gold Colours

Yellow Gold

Gold has a warm yellow colour in its purest form. Even when it is alloyed with other metals such as silver, nickel or palladium to make 14k or 18k Gold, it retains a yellowish colour. The richness of the Gold colour is directly affected by the percentage of Gold in its alloys: therefore, 18k Gold has a richer Gold colour than 14k Gold.

White Gold

To give White Gold its brilliant shiny white luster, the final process of making White Gold involves plating the metal with a layer of Rhodium. Rhodium is a shiny white metal, which is extremely hard and durable. Over time, withregular wear, the Rhodium plating may wear off revealing the yellow Gold underneath, and can be easily repaired by a jeweller who can redo the Rhodium plating.

BIS Hallmarking

Hallmarking of gold jewellery is carried out on a voluntary basis under the Bureau of Indian Standards Act, 1986, in accordance with the Vienna Convention's international criteria on hallmarking.

A Hallmark consists of five components -

The BIS Mark

The fineness number (corresponding to given Karatage)

The Assaying and Hallmarking Centre's mark

The jeweller's mark

The year of marking denoted by a code letter and decided by BIS (e.g. the code letter 'A' was approved by BIS for the year 2000, 'B' being used for the year 2001 and 'C' for 2002).

The BIS hallmark, a mark of conformity widely accepted by the consumer bestows the additional confidence to the consumer on the purity of gold jewellery.

Deviations in degree of purity of fine metal and observance of operations not in conformance to the system may result in cancellation of BIS license, and invoke legal proceedings for penalties under the BIS Act, Rules and Regulations.

The principal objective of assaying and hallmarking is to protect a consumer against victimization of irregular gold quality.